Systems and methods for intramedullary nail implantation

ABSTRACT

Intramedullary nails, aiming guide assemblies, and methods. The aiming guide assembly can include an aiming guide having a collet and a connection bolt configured to engage a connection bolt driver. The connection bolt may be self-retaining and engage with the connection bolt driver in a manner to prevent unintentional disengagement.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.16/153,873, filed Oct. 8, 2018 (published as U.S. Pat. Pub. No.2019-0038326), which is a continuation-in-part of U.S. application Ser.No. 15/441,457, filed on Feb. 24, 2017 (published as U.S. Pat. Pub. No.2018-0078294), which is a continuation-in-part of U.S. application Ser.No. 15/423,773, filed Feb. 3, 2017 (now U.S. Pat. No. 10,251,691), whichis a continuation-in-part of U.S. application Ser. No. 15/272,850, filedon Sep. 22, 2016 (published as U.S. Pat. Pub. No. 2018-0078299), thecontents of which are incorporated herein by reference in theirentireties for all purposes.

TECHNICAL FIELD

The present technology is generally related to intramedullary nailimplantation for treatment of bone fractures. In particular, severalembodiments are directed to systems and methods for implanting anintramedullary nail for immobilizing bone fractures.

BACKGROUND

The significant long bones of the extremities are the humerus, radiusand ulna of the upper extremity and the femur and tibia of the lowerextremity. Following an injury to the long bone, and in particular,injuries resulting in one or more fractures of the long bone, one ormore fixation devices may be used to immobilize the fracture fragmentsand stabilize the long bone. Bone fractures can be treated with screwsor other fixation devices inserted into or through the bone to stabilizeit once the fractured portions have been brought into proper alignment.Femoral neck fixation, for example, can be used to treat hip fracturesby inserting an intramedullary nail into the medullary cavity of thefractured femur followed by insertion of a fixation screw into thefemoral neck/head at an angle relative to the intramedullary nail.Similarly, other long bone fractures can be treated by inserting anintramedullary nail into the intramedullary canal of the bone andproviding the appropriate proximal and/or distal fixation. Traditionalintramedullary devices may suffer from a number of disadvantages,however. For example, they may be susceptible to implant failure anddifficulty in alignment of the fixation screw with respect to theintramedullary nail. Accordingly, there is a need for improved systemsand methods for intramedullary nail implantation.

SUMMARY

Intramedullary nails, systems, insertion tools and assemblies, andmethod of treatment are provided. The intramedullary nails may besuitable for implanting within a medullary canal of a fractured longbone and subsequently providing proximal fixation and/or distalfixation, for example, with one or more anchors, fasteners, fixationscrews, or the like. Suitable long bones may include the humerus,radius, ulna, femur, tibia, or the like. Although generally describedwith reference to the femur and tibia, it will be appreciated that theintramedullary nail and system may be adapted for use with any longbone.

According to one aspect, an intramedullary nail is provided. Theintramedullary nail may comprise a generally elongate body extendingfrom a first, distal end to a second, proximal end. The distal end mayinclude one or more openings configured to receive one or more boneanchors or fasteners that extend transversely through the distal endintramedullary nail, and thereby configured to secure the distal end ofthe nail. The proximal end may also include one or more openingsconfigured to receive one or more bone anchors or fasteners that extendtransversely through the proximal end of the intramedullary nail, andthereby configured to secure the proximal end of the nail.

In one aspect, a system for inserting an intramedullary nail into a boneis provided. The system includes an intramedullary nail with an openingor aperture formed therein. An insertion tool can temporarily engagewith an end of the intramedullary nail during implantation, and releasefrom the nail once the procedure is complete. A receiving feature for aguide sheath (e.g., a hole, recess, etc.) is disposed in the handleportion and can receive a guide sheath therethrough. The receivingfeature defines an axis such that, when the intramedullary nail iscoupled to the coupling portion, a guide sheath inserted through thereceiving feature substantially aligns with the aperture in theintramedullary nail. A first retention member is disposed in theinsertion tool adjacent to the guide sheath receiving feature. The firstretention member can interact with a second retention member on theguide sheath to form a ratchet-like mechanism that restrict movement ofthe guide sheath with respect to the receiving feature. A retentionrelease mechanism can be located on a lower portion (e.g., a bottomsurface) of the insertion tool. A guide wire receptacle (e.g., a hole,recess, etc.) can receives a guide wire therethrough and is positionedsuch that, when the intramedullary nail is coupled to the couplingportion, a guide wire inserted through the receiving feature runs alongan axis adjacent to the side surface of the intramedullary nail.

In another aspect, a method for inserting an intramedullary nail into apatient is provided. The method includes inserting a nail into amedullary canal of a patient along a first axis. For insertion, the nailis coupled at its proximal end to an insertion tool. A guide wire isinserted through a guide wire hole in the insertion tool along a secondaxis such that the guide wire runs nearby or adjacent to a side surfaceof the nail. A screw or other bone fixation device is inserted through areceptacle (e.g., a hole, recess, or other suitable structure) formed inthe insertion tool such that the screw passes through an aperture formedin the nail.

In accordance with another aspect, an implant is provided. The implantincludes an intramedullary nail that is elongated along a first axis.First and second openings or apertures are disposed in a proximalportion of the nail. The first aperture defines a second axis transverseto the first axis, and the second aperture defines a third axistransverse to the first axis. The third axis intersects with the secondaxis at a point spaced apart from the nail. In some embodiments, thefirst screw can be inserted through the first aperture along the secondaxis and a second screw can be inserted through the second aperturealong the third axis. The second screw can be at least partiallyinserted through a slot in the first screw such that the two screwsinterlock. The second screw can be shorter than the first screw but longenough that at least a threaded distal tip extends beyond the slot inthe first screw to provide some purchase in the bone.

In accordance with another aspect, an implant is provided. The implantincludes an intramedullary nail having a body elongated along a firstaxis. The body has a proximal portion and a distal portion. A firstaperture is formed in the proximal portion and defines a second axistransverse to the first axis at a first angle. A second aperture isformed in the proximal portion and defines a third axis transverse tothe first axis at a second angle. The third axis intersects with thesecond axis at the first axis and the first and second angles arecomplementary angles.

In accordance with another aspect, an intramedullary system configuredto stabilize bone is provided. The system comprises an intramedullarynail and one or more headless fasteners or screws. The headless fastenerextends from a first end to a second end. The headless fastener has ashaft configured to be positioned through the first aperture or thesecond aperture in the intramedullary nail and the first end (e.g., insome instances a threaded head) of the headless fastener is configuredto be positioned against or within the bone. Unlike traditional headedscrews which sometimes cause pain or irritation to patients, one or moreheadless screws or fasteners can be used when securing the distal and/orproximal ends of the intramedullary nail, thereby resulting in a systemwith superior patient outcomes.

In accordance with another aspect, a system for inserting anintramedullary nail into a bone is provided. The system includes anintramedullary nail having a proximal end, a distal end, at least oneside surface extending between the proximal end and the distal end, andan aperture through the intramedullary nail. An insertion tool includesa handle portion, a coupling portion and an aiming guide. The handleportion defines a first connection assembly. The coupling portionextends from the handle portion and is configured to removably couple tothe proximal end of the intramedullary nail. The aiming guide has a bodywith at least one support block and a second connection assembly. Thefirst and second connection assemblies are configured to releasablyinterconnect the handle portion and the aiming guide. The at least oneguide block defines a guide sheath hole configured to receive a guidesheath therethrough. The guide sheath hole is positioned such that, whenthe intramedullary nail is coupled to the coupling portion, the guidesheath hole substantially aligns with the aperture in the intramedullarynail.

In accordance with another aspect, a connection assembly forinterconnecting an intramedullary nail and insertion tool is provided.The intramedullary nail extends between a proximal end and a distal endand has a circumferential slot defined within the proximal end. Theinsertion tool includes an aiming arm with a hole defined therein. Theconnection assembly includes an alignment tip having a hollow bodyextending from a proximal end to a distal end with the proximal endconfigured to be securely connected within the hole of the aiming arm.An expanding collet has a hollow body extending from a collet proximalend to a collet distal end. The collet distal end has a radiallyoutwardly extending collar and internal threads. The collet body definesaxial slots extending from the distal end of the body which allow thedistal end of the body to compress radially inwardly, thereby allowingthe collar to pass through the alignment tip through passage and intothe circumferential slot of the intramedullary nail. A connecting bolthas a threaded shaft and extends through the hole in the aiming arm andinto threaded engagement with the internal threads of the expandingcollet such that the collar is pushed outwardly to its major diameter.

Also provided are kits including intramedullary nails of varying shapesand sizes, bone anchors, fasteners, insertion tools, and components forinstalling the same.

According to still another aspect, an aiming guide for inserting anintramedullary nail into a bone includes a generally arcuate or“J-shaped” body having an elongate proximal handle portion and agenerally arcuate distal implant alignment tip connector portion havinga distal implant alignment tip extending parallel to a longitudinal axisof the proximal handle portion. The handle portion includes a firstattachment location for releasably attaching a first module and thedistal implant alignment tip portion includes a second attachmentlocation for releasably attaching a second module.

In accordance with yet another aspect, an aiming guide assembly includesa generally “J-shaped” aiming guide having an elongate proximal handleportion and a generally arcuate distal implant alignment tip connectorportion. The distal implant alignment tip connector portion has a distalimplant alignment tip extending along a tip axis parallel to alongitudinal axis of the proximal handle portion. A recon module isreleasably attached to a proximal end of the proximal handle portion andan oblique module is releasably attached to the distal implant alignmenttip portion.

According to another aspect, an aiming guide assembly includes an aimingguide having an elongate proximal handle portion and a generally arcuatedistal implant alignment tip connector portion. The aiming guide has anelongate proximal handle portion and a generally arcuate distal implantalignment tip connector portion. The distal implant alignment tipconnector portion has a distal implant alignment tip extending along atip axis parallel to a longitudinal axis of the proximal handle portion.A first attachment is releasably attached to a proximal end of theproximal handle portion and a second attachment is releasably attachedto the distal implant alignment tip portion.

According to another aspect, an aiming guide for inserting anintramedullary nail into a bone includes a collet configured to engagethe intramedullary nail, a connection bolt configured to engage thecollet to connect the collet with the intramedullary nail, and aconnection bolt driver configured to engage the connection bolt. Theconnection bolt may include a head containing a circlip. The circlip maybe configured to splay open upon insertion of the connection bolt driverinto the head and provide tension around the connection bolt driver toretain the connection bolt driver in the head of the connection bolt.

According to another aspect, an aiming guide for inserting an implantinto a bone includes a collet configured to engage the intramedullarynail, a connection bolt configured to engage the collet to connect thecollet with the implant, and a connection bolt driver configured toengage the connection bolt. The connection bolt may include a headcontaining a circlip. The circlip may be configured to splay open uponinsertion of the connection bolt driver into the head and providetension around the connection bolt driver to retain the connection boltdriver in the head of the connection bolt.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIGS. 1A and 1B illustrate a system for implanting an intramedullarynail.

FIGS. 2A-2C illustrate various views of an insertion handle of thesystem shown in FIGS. 1A and 1B.

FIGS. 3A-3F illustrate steps of implanting an intramedullary nail into afractured femur.

FIGS. 4A-4D illustrate various views of an intramedullary nail and afirst fixation device.

FIGS. 5A-5D illustrate various views of the first fixation deviceinserted through the intramedullary nail.

FIGS. 6A-6D illustrate various views of a second fixation device and theintramedullary nail with the first fixation device inserted therein.

FIGS. 7A-7D illustrate various views of the second anchor insertedthrough the intramedullary nail and the first fixation device.

FIGS. 8A-8C illustrate steps of implanting an intramedullary nail withinterlocking fixation devices into a fractured femur.

FIGS. 9A-9N illustrate various views of an illustrative intramedullarynail.

FIGS. 10A-10C illustrate steps of a method of calculating the radius ofcurvature of a femoral nail.

FIGS. 11A-11E illustrate various views of an insertion tool andintramedullary nail connection assembly.

FIGS. 12A-12K illustrate various views of a locking screw andcorresponding torque driver head.

FIGS. 13A-13F illustrate various views of a headless locking screw.

FIGS. 14A-14C illustrate various views of a nail including a lockingscrew opening with a 2 start thread configuration.

FIGS. 15A-15C illustrate various views of a screw compression washer.

FIGS. 16A-16H illustrate various views of illustrative tibial nails.

FIGS. 17A-17L illustrate various views of illustrative insertionsystems.

FIG. 18 is a perspective view of a femoral nail aiming guide accordingto an exemplary embodiment.

FIG. 19 is a perspective view of a recon module for releasableconnection to the aiming guide of FIG. 18.

FIG. 20 is a perspective view of an oblique module for releasableconnection to the aiming guide of FIG. 18.

FIG. 21 is a perspective view of an aiming guide assembly including therecon module of FIG. 19 and the oblique module of FIG. 20, bothconnected to the aiming guide of FIG. 18.

FIG. 22 is a reverse perspective view of the aiming guide assembly ofFIG. 21.

FIG. 23 is a perspective view of the aiming guide assembly of FIG. 21with two screws inserted through the recon module and into a femoralnail.

FIG. 24 is a reverse perspective view of the aiming guide assembly ofFIG. 23 with two screws inserted through the recon module and into thefemoral nail.

FIG. 25 is a perspective view of the aiming guide assembly of FIG. 21with one screw inserted through the recon module and one screw insertedthrough the oblique module and into a femoral nail.

FIG. 26 is a perspective view of the aiming guide assembly of FIG. 21with one screw inserted through the aiming guide and one screw insertedthrough the oblique module and into a femoral nail.

FIG. 27 is a perspective view of a femoral nail aiming guide accordingto another exemplary embodiment.

FIG. 28 is a perspective view of an exemplary aiming guide and boltdriver consistent with the principles of the present disclosure.

FIG. 29A-29B is a perspective view of an exemplary connection boltconsistent with the principles of the present disclosure.

FIG. 30 is a perspective view of an exemplary connection bolt andconnection bolt driver consistent with the principles of the presentdisclosure.

DETAILED DESCRIPTION

In the drawings, like numerals indicate like elements throughout.Certain terminology is used herein for convenience only and is not to betaken as a limitation on the present device. The terminology includesthe words specifically mentioned, derivatives thereof and words ofsimilar import. The embodiments illustrated below are not intended to beexhaustive or to limit the device to the precise form disclosed. Theseembodiments are chosen and described to best explain the principle ofthe device and its application and practical use and to enable othersskilled in the art to best utilize the device.

Reference herein to “one embodiment” or “an embodiment” means that aparticular feature, structure, or characteristic described in connectionwith the embodiment can be included in at least one embodiment of thedevice. The appearances of the phrase “in one embodiment” in variousplaces in the specification are not necessarily all referring to thesame embodiment, nor are separate or alternative embodiments necessarilymutually exclusive of other embodiments. The same applies to the term“implementation.”

As used in this application, the word “exemplary” is used herein to meanserving as an example, instance, or illustration. Any aspect or designdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects or designs. Rather, use ofthe word exemplary is intended to present concepts in a concretefashion.

Intramedullary nails, systems, insertion tools, and method of treatmentare provided. The intramedullary nails may be suitable for implantationwithin the intramedullary canal of a fractured long bone andsubsequently providing proximal fixation and/or distal fixation, forexample, with one or more anchors, fasteners, fixation screws, or thelike. Suitable long bones may include the humerus, radius, ulna, femur,tibia, or the like. Although further described with reference to hipfractures of the femur or fractures of the tibia, it will be appreciatedthat the intramedullary nail and system may be adapted for use with anylong bone.

In conventional hip fracture fixation techniques, there are four mainfailure modes: axial cutout, cephalad cutout, proximal fragmentrotation, and nonunion. “Cutout” is the term for hip screw subsidenceinto the articular surface of the hip. Cutout can occur in either acephalad (toward the head) or axial direction (along the axis of the hipscrew). Axial cutout is the result of an implant with a small axialprofile that provides little resistance to axial translation. Axialcutout can be addressed by the “controlled collapse” features on certainmodern hip fracture nails; the hip screw is allowed to translate throughthe nail, even after the set screw is locked in place. Cephalad cutoutis the radial translation of the nail which is the result of a narrowimplant that “windshield wipers” through the weak cancellous bone in thehip. Proximal fragment rotation is the result of a circular profile hipscrew that acts as a fulcrum to the proximal hip fragment. Fracturenonunion is the result of biologic or mechanical factors that areincompatible with the bone healing process. Biologic factors of thepatient are not controllable by the implant. Mechanical factors arethose that typically allow fixation that is too rigid or too flexible.Nonunion is usually the precursor to one of the other three failuremodes. Occasionally, nonunion will cause the nail to break in fatiguebefore the bone fails.

The intramedullary nails and systems described herein may address one ormore of these failure modes. In some embodiment, the intramedullary nailincludes proximal and distal locking, for example, to prevent cutout. Inother embodiments, the intramedullary nail may include proximal lockingincluding two interlocking fixation devices (e.g., screws), for example,by providing converging and diverging purchase, along with bony fixationin the calcar of the femur, which is the strongest portion of the hipbone. Accordingly, the risk of failure due to cutout and/or rotation canbe reduced.

Additionally, some intramedullary nail implantation systems fail toadequately address the problems of fragment rotation duringimplantation. Rotation occurs when fragments of the bone rotate aboutthe axis of the screw during the implantation procedure. Conventionalanti-rotation technologies require the use of additional instruments orare limited to a single wire placement. In some embodiments, aninsertion tool is directly coupled to the intramedullary nail andadditional instruments are not needed for the placement of ananti-rotation guide wire and allow the user to place one or more guidewires anterior and/or posterior to the nail. These guide wires can bepositioned to prevent the distal fragments of the femoral head and neckfrom rotating about the axis of the anchor during the procedure.

Some systems may be susceptible to backout during the implantationprocedure. Backout occurs when the guide sheath used to insert the screwthrough the intramedullary nail moves proximally away from the bone.Conventional systems either have no features to prevent backout or elseprovide backout prevention measures that obstruct the normal positioningof the hands during the procedure, resulting in the risk of releasingthe guide sheaths and dropping them to the floor. Ratchets on theinsertion tool may have the release button facing towards the gripportion on the insertion tool and may present the danger of the user'shand slipping and inadvertently pressing the button. Accidentallypressing the button could result in releasing the sheath and causing thesheath to fall on the floor. In some embodiments, a backout preventionsystem (e.g., a ratchet system) may be disposed on the lower end of theinsertion tool, which allows a user to have a hand placed on the grip ofthe insertion tool without the risk of inadvertently pressing theratchet release button.

Further specific details of several embodiments of the presenttechnology are described below with reference to FIGS. 1A-8C. Althoughmany of the embodiments are described below with respect to devices,systems, and methods for implantation of intramedullary nails, otherembodiments are within the scope of the present technology.Additionally, other embodiments of the present technology can havedifferent configurations, components, and/or procedures than thosedescribed herein. For example, other embodiments can include additionalelements and features beyond those described herein, or otherembodiments may not include several of the elements and features shownand described herein.

For ease of reference, throughout this disclosure identical referencenumbers are used to identify similar or analogous components orfeatures, but the use of the same reference number does not imply thatthe parts should be construed to be identical. Indeed, in many examplesdescribed herein, the identically numbered parts are distinct instructure and/or function.

FIGS. 1A and 3F illustrate one example of an intramedullary nail 109,which may comprise a generally elongate body extending from a first,distal portion or end 110 to a second, proximal portion or end 111. Theelongate body may be in the form of an elongate tubular rod configuredto extend longitudinally within the intramedullary canal of a fracturedbone. The elongate rod may be hollow or may be solid along its length.The elongate body may be substantially straight along a longitudinalaxis of the nail 109 or may comprise one or more curves or bends toconform to the anatomical shape of the intramedullary canal. Thecross-section of the nail 109, taken at a right angle to a centrallongitudinal axis of the intramedullary nail 109, may be circular, oval,elliptical, or of any other suitable cross-dimensional shape. Theproximal portion 111 may have an enlarged diameter or head portionrelative to the distal portion 110 of the nail 109. The enlarged headportion 111 may be sized and configured to be received in the greatertrochanter region of the femur. The intramedullary nail 109 may beconfigured to be positioned in the proximal end of the femur forcephalomedullary fixation. It is envisioned, however, that theintramedullary nail 109 may be configured to be positioned through otherapproaches and locations (e.g., distal end) depending on the bone (e.g.,femur, tibia) and type of fracture.

The distal end 110 may include one or more openings 125 configured toreceive one or more bone anchors, fasteners, or distal fixation devices147 that extend transversely through the distal end 110 of theintramedullary nail 109, and are thereby configured to secure the distalend 110 of the nail 109 within the canal. The distal fixation devices147 may include a bone screw or anchor configured for distal locking ofthe nail 109. The distal fixation device 147 may include traditionalpolyaxial or fixed angle locking bone screws and anchors known in theart.

The proximal end 111 may also include one or more openings 123configured to receive one or more bone anchors or fasteners 119 thatextend transversely through the proximal end 111 of the intramedullarynail 109, and are thereby configured to secure the proximal end 111 ofthe nail 109 within the canal. The proximal fixation devices 119 mayinclude a bone screw or anchor configured for proximal locking of thenail 109. The fixation device 119 may be a calcar screw or anchorconfigured to be aimed at a calcar region of the proximal humerus, whichmay constitute the best quality bone in the region. The opening 123 andanchor 119 may be angled about 100-150°, 110-140°, or about 120-135°relative to the nail 109 to engage the calcar region of the bone. Thecalcar screw 119 may have an enlarged diameter relative to the distalscrew 147. The proximal fixation device 119 may include traditionalpolyaxial or fixed angle calcar screws and anchors known in the art. Theproximal end 111 may also include additional openings 123, for example,for one or more cross-locking devices (e.g., device 205 described inmore detail below).

The intramedullary nail 109 and anchors 119, 147 may be comprised of anysuitable biocompatible materials. The intramedullary nail 109 andanchors 119, 147 may be comprised of titanium, cobalt chrome,cobalt-chrome-molybdenum, stainless steel, tungsten carbide, carboncomposite, plastic or polymer—such as polyetheretherketone (PEEK),polyethylene, ultra high molecular weight polyethylene (UHMWPE),resorbable polylactic acid (PLA), polyglycolic acid (PGA), combinationsor alloys of such materials, or other appropriate biocompatiblematerials that have sufficient strength to secure and hold bone, whilealso having sufficient biocompatibility to be implanted into a body.

FIGS. 1A and 1B illustrate perspective and side views, respectively, ofone embodiment of a system 101 for implanting an intramedullary nail109. The system 101 includes an insertion tool 103 that has a couplingportion 105 and a handle portion 107. In some embodiments, the couplingportion 105 and the handle portion 107 can be separate parts that areremovably joined together, while in other embodiments the couplingportion 105 and the handle portion 107 can be different regions of asingle, integrally formed component. The coupling portion 105 releasablyengages or couples to the proximal portion 111 of the nail 109. Forexample, the free end of the coupling portion 105 can be provided with asnap-fit design to temporarily retain a portion of the intramedullarynail 109 prior to insertion of a fixation device 119 therethrough.However, those skilled in the art will understand that other couplingmechanisms may be employed.

The handle portion 107 may include one or more openings 127, 129configured to receive one or more guide wires 113, 115. In oneembodiment, the system 101 may include first and second guide wires 113,115 as well as an optional guide sheath 117 through which the fixationdevice 119 may pass (e.g., the fixation device 119 can be inserted usingthe driver 121). As illustrated, the first and second guide wires 113,115 may pass on opposing sides of both the nail 109 and the fixationdevice 119 (e.g. on posterior and anterior sides). Although theillustrated embodiment shows two guide wires, in other embodiments asingle guide wire and corresponding guide wire hole may be used. Instill other embodiments, three or more guide wires may be used.Additionally, the position and orientation of the guide wire holes canvary in different embodiments, for example being disposed moreproximally or more distally along the insertion tool, etc.

As illustrated, the insertion tool 103 allows the user to place one ormore guide wires 113, 115. In one embodiment, the guide wires 113, 155are positioned both anterior and posterior to the nail 109. The guidewires 113, 115 may be positioned in this manner to prevent the distalfragments of the bone (e.g., distal fragments of the femoral head andneck) from rotating about the axis of the fixation device 119 when thefixation device 119 is advanced through the nail 109 and into the boneduring the procedure. The handle portion 107 of the insertion tool 103may include two guide wire receiving features such as holes 127, 129 onthe opposing sides of the tool 103 that allow guide wires 113, 115 topass through the respective holes. The guide wires 113, 115 are passedthrough the soft tissue and into the bone to help stabilize theinsertion tool 103. In this configuration, the insertion tool 103 maynot require any other instruments to guide the wires 113, 115 into thepatient. The insertion tool 103 can achieve stability by resisting bothrotational movement about the axis of the nail 109 as well as axialtranslation along the axis of the nail 109.

FIGS. 2A-2C illustrate various views of the insertion tool 103 of thesystem 101 shown in FIGS. 1A and 1B. In particular, FIG. 2A is apartially exploded perspective view of the insertion tool 103 adjacentto the guide sheath 117, FIG. 2B is a perspective view of the insertiontool 103 with the guide sheath 117 partially inserted therein, and FIG.2C is an enlarged partial cross-sectional view of the engagement betweenthe guide sheath 117 and the insertion tool 103.

The guide sheath 117 can be removably inserted through a guide sheathreceiving feature such as a hole 131 formed in the handle portion 107 ofthe insertion tool 103. The guide sheath hole 131 defines an axis thatintersects with a first aperture 123 in the nail 109. The guide sheath117 can be positioned through the guide sheath hole 131 such that itsubstantially aligns with the first aperture 123 in the nail 109, whichis configured to receive fixation device 119 aimed at the calcar regionof the bone. The guide sheath 117 can include a first retention member133 on an outer surface of the guide sheath 117. The first retentionmember 133 can include, for example, ridged teeth, protrusions, or othersuch surface configured to engage with a corresponding second retentionmember 135 disposed within the guide sheath hole 131. The secondretention member 135 can likewise include one or more ridges orprotrusions. Together the first and second retention members 133, 135form a retention mechanism 137 that allows the guide sheath 117 to beratcheted towards the intramedullary nail 109 while restricting movementof the guide sheath 117 away from the intramedullary nail. The retentionrelease mechanism 139 can disengage the second retention member 135 fromthe first retention member 133 when pressed by a user. For example, theretention release mechanism 139 can be a button disposed on a lowersurface 141 of the handle portion 107. Positioning this retentionrelease mechanism 139 on the lower surface 141 of the insertion handlemay prevent a user from accidentally releasing the guide sheath 117while operating the device (e.g., while grasping the handle portion107).

FIGS. 3A-3F illustrate one method of steps of implanting anintramedullary nail into a fractured femur 143. Referring first to FIG.3A, a proximal end of the femur 143 can be accessed and the medullarycavity of the femur 143 can be reamed using a bone drill and reamer 145.Next, as shown in FIG. 3B, the intramedullary nail 109 is coupled to theinsertion tool 103 and the intramedullary nail 109 is disposed withinthe reamed cavity of the femur 143. In FIG. 3C, when used, one or moreof the first and second guide wires 113 and 115 may be inserted throughthe soft tissue, for example, along parallel trajectories on opposingsides of the nail 109. The guide wires 113, 115 can limit or preventinadvertent rotation of distal fragments of the femur 143 after the nail109 is in position. The proximal fixation device 119 (e.g., a lag screwor other suitable bone anchor) is also passed through the first aperture123 in the nail 109 and into the head/neck region of the femur 143. InFIG. 3D, the guide wires 113, 115 are retracted and in FIG. 3E, thedistal fixation device 147 can additionally be inserted through thedistal aperture 125 in the nail 109. The distal device 147 can bepositioned using the guide sheath 117, which is positioned throughanother opening in the handle portion 107, such that the sheath 1117 isaligned with the distal opening 125 in the nail 109. In FIG. 3F, theinsertion tool 103 is disengaged from the nail 109, which is now securedin place via the proximal fixation device 119 and the distal fixationdevice 147. As shown, the nail 109 may extend along a portion of thelength of femur 143. It is also contemplated, however, that the nail 109may be of different sizes and shapes, for example, of longer lengthsand/or different diameters to accommodate different anatomies andfractures.

FIGS. 4A-4D illustrate another embodiment of an intramedullary nail 201,similar to intramedullary nail 109, with the addition of a cross-lockingfeature for proximal locking of the nail 201. Intramedullary nail 201may include any of the features described above with respect tointramedullary nail 109. Intramedullary nail 201 may further include twointerlocking proximal fixation devices 203, 205 (e.g., bone anchors,fasteners, or screws), for example, by providing converging anddiverging purchase, along with bony fixation in the calcar of the femur229, which is the strongest portion of the hip bone. Accordingly, therisk of failure due to cutout and/or rotation may be reduced.

FIGS. 4A-4D show side, side cross-sectional, and two perspective views,respectively, of the intramedullary nail 201 adjacent to a firstfixation device 203. FIGS. 5A-5D illustrate side, side cross-sectional,and two perspective views, respectively, of the first, proximal fixationdevice 203 inserted through the intramedullary nail 201. FIGS. 6A-6Dillustrate side, side cross-sectional, and two perspective views,respectively, of the system with a second, cross-locking fixation device205 adjacent to the intramedullary nail 201 with the first fixationdevice 203 inserted therein. FIGS. 7A-7D illustrate side, sidecross-sectional, and two perspective views, respectively, of the systemwith the second fixation device 205 inserted through both theintramedullary nail 201 and the first fixation device 203, therebycreating a cross-locking feature for proximal locking of the nail 201.

Referring to FIGS. 4A-8C together, the intramedullary nail 201 isconfigured to receive both the first and second fixation devices 203 and205 therein. The intramedullary nail 201 includes an elongated body 207having first and second apertures 209 and 211 formed therethrough in aproximal region 213, as well as a third aperture 215 formed in a distalregion 217. The first aperture 209 can be sized and configured toreceive the first fixation device 203 therethrough and the secondaperture 211 can be sized and configured to receive the second fixationdevice 205 therethrough.

The first fixation device 203, may be the same or similar to theproximal fixation device 119, described herein, and may include a bonescrew or anchor configured for proximal locking of the nail 201. Forexample, the first fixation device 203 may be a calcar screw or anchorconfigured to be aimed at a calcar region of the proximal humerus. Thecalcar screw 203 may have a threaded portion at its distal tip and anon-threaded portion along a substantial length of the screw 203. Thecalcar screw 203 may include traditional polyaxial or fixed angle calcarscrews and anchors known in the art.

The second fixation device 205 may also include a bone screw or anchorconfigured for proximal locking of the nail 201. This bone anchor orscrew 205 may be substantially smaller in length and diameter relativeto the calcar screw 203. The bone anchor or screw 205 is substantiallysized and configured to be positioned through second opening 211 in theproximal end of the nail 201 and into a channel 219 in the firstfixation device 203. Thus, the second device 205 is configured tointerlock with the first fixation device 203, for example, enhancedpurchase and bony fixation to the bone. Although shown with the secondfixation device 205 positioned above the first fixation device 203 andangled downwardly into contact with the first fixation device 203, it isalso envisioned that these relative positons may be reversed or thefixation devices 203, 205 may otherwise be angled with respect to oneanother in order to interlock the devices 203, 205 with one another. Thesecond fixation device 205 may be configured to pass through a slot orchannel 219 formed in the first fixation device 203. This interlockingfeature of the first and second fixation devices 203, 205 can preventcutout and rotation by providing converging and diverging purchase. Inthe case of a femur, this can also provide bony fixation in the calcar.The elongated slot 219 in the first fixation device 203 allows forcontrolled collapse, which leverages the natural compression betweenfragments from weight bearing or ligamentotaxis. Limited collapse iscontrolled by the length of the slot 219 to prevent the uncontrolled andexcessive shortening of the femoral neck. The first fixation device 203may include distal threads 221 and a proximal drive interface 223configured to engage with a driver (not shown). The second fixationdevice 205 may have a narrower diameter than the first fixation device203 such that the second fixation device 205 can pass through the slot219 in the first fixation device 203. The second fixation device 205 mayalso include distal threads 225 and a proximal drive interface 227configured to engage with a driver (not shown).

The slot 219 can be disposed in the mid-shaft of the first fixationdevice 203 and may be sized and configured to allow the second fixationdevice 205 to pass therethrough. The slot 219 may be longer thannecessary to allow translation of the first fixation device 203 afterthe second fixation device 205 is in place. The slot 219 may be strongenough to prevent rotation of the first fixation device 203 after thesecond fixation device 205 is in position. The slot 219 may have beveledproximal and distal edges to maximize material in the first fixationdevice 203 while allowing proximal and distal clearance of the secondfixation device 205. The slot 219, in the first fixation device 203, maybe symmetric to allow positioning of the second fixation device 205 in180° increments, for example.

In at least one embodiment, a locking device 230, such as a set screw orwasher, may be used to lock the first and/or the second fixation devices203, 205 into position. As best seen in FIG. 7B, the locking device 230may be threaded through a hollow interior portion of the nail 201. Thelocking device 230 may have external threads, which are sized andconfigured to correspond to mating internal threads along the hollowinterior portion of the nail 201. As the locking device 230 is threadeddownwardly and comes into contact with the first or second fixationdevices 203, 205, the respective fixation device 203, 205 is locked intopositon relative to the nail 201. In some embodiments, the interlockingfixation devices 203, 205 can be used selectively. For example, thethreaded locking device 230 may be threaded to engage the secondfixation device 205; alternatively, the threaded locking device 230 maybe threaded further down to lock the first fixation device 203, forexample, if the second fixation device 205 is not used. This allowsusers the choice of a traditional or interlocking constructintraoperatively.

An insertion tool 103 for implanting the system including the nail 201and the interlocking first and second fixation devices 203 and 205 canbe substantially similar to the system 101 described above with respectto FIGS. 1A-2C, except that an additional guide sheath hole may beformed in the handle portion 107 to accommodate a guide sheath along anappropriate trajectory to insert the second fixation device 205 throughthe second aperture 211 in the nail 201 and into engagement with thefirst fixation device 203.

FIGS. 8A-8C illustrate one method of steps of implanting anintramedullary nail 201 with interlocking fixation devices 203, 205 intoa fractured femur 229. Referring first to FIG. 8A, the nail 201 has beeninserted into a reamed medullary cavity of the femur 229 and the firstfixation device 203 has been inserted through the first aperture 209 inthe nail 201, similar to the technique described above with respect toFIGS. 3A-3D. Referring to FIG. 8B, a distal fixation device 231 can beinserted through the third aperture 215 in the nail 201, similar to thetechnique described above with respect to FIG. 3E. Referring to FIG. 8C,the second fixation device 205 is inserted through the second aperture211 in the nail 201 and through the slot 219 in the first fixationdevice 203. As noted, these intersecting first and second fixationdevices 203, 205 provide additional purchase in the head and neck regionof the femur 229, and in particular the second fixation device 205 canprovide bony fixation in the calcar. Accordingly, the interlocking firstand second fixation devices 203, 205 can provide for improved stabilityand protection against common modes of intramedullary nail implantfailure.

FIGS. 9A-9N illustrate another example of an intramedullary nail 309,which may comprise a generally elongate body extending from a first,distal portion or end 310 to a second, proximal portion or end 311. Theelongate body may be in the form of an elongate tubular rod configuredto extend longitudinally within the intramedullary canal of a fracturedbone. The elongate rod may be hollow or may be solid along its length.The elongate body may be substantially straight along a longitudinalaxis of the nail 309 or may comprise one or more curves or bends toconform to the anatomical shape of the intramedullary canal. In theembodiment of the nail 309 illustrated in FIG. 9A, the nail 309 may beutilized in a piriformis fossa entry and the curvature may be providedin the AP (anteroposterior) direction. This curvature allows the nail309 to be used either antegrade (FIG. 9A) or retrograde (FIG. 9D), aswell as in the right leg or left leg. In the embodiment illustrated inFIG. 9C, the nail 309′ has curvature in the AP direction as well as abend in the ML (medial-lateral) direction to facilitate entry at the tipof the greater trochanter. In other aspects, the nails 309 and 309′ arethe same unless otherwise described. The cross-section of the nail 309,taken at a right angle to a central longitudinal axis of theintramedullary nail 309, may be circular, oval, elliptical, or of anyother suitable cross-dimensional shape.

Referring to FIGS. 10A-10C, a process of calculating the AP curvature ofthe nail 309 will be described. The radius of curvature of the nail 309may change depending on the length of the nail 309 so that the curvaturecan match the anatomical curvature of the femur into which the nail 309is being inserted. Often-times, in longer femurs (taller patients), thecurvature has too small a radius, and surgeons struggle to insert thenail without causing bone damage. The method of radius planning based ondisplacement described herein reduces the likelihood of a problem byoffering a more anatomically correct (larger) radius.

As shown in FIG. 10A, the femur endpoints may be in a vertical line. Assuch, the AP radius of curvature can be calculated using tangent circlesif a valid starting point is assumed, for example, a nail length L of mmhaving a radius R. Turning to FIG. 10B, each tangent circle will have aradius R. Drawing a right triangle from the center C of the tangentcircle, with R as the hypotenuse and ½ the nail length L as one leg ofthe triangle, the other leg will have a length z. Due to the curvature,the point where the legs 1/2L and z meet will be spaced a distance yfrom the tangent point T. As such, R=y+z and R²=L²/4+z². Combining theformulas results in R=y/2+L²/8y. Utilizing the initial assumption, theconstant y can be calculated. With the constant y calculated, the radiusR of curvature for each length L can be found. Utilizing the assumptionof a nail length having a radius R, the following is a table ofcalculated radius R for various lengths L.

Nail Length (mm) AP Bow (m) 160-300 1.0 310-400 1.2 410-500 1.4

Referring again to FIGS. 9A-9N, the distal end 310 of the nail 309 mayinclude one or more distal openings 312-318 configured to receive one ormore bone anchors, fasteners, or distal fixation devices 330, 332 thatextend transversely through the distal end 310 of the intramedullarynail 309, and are thereby configured to secure the distal end 310 of thenail 309 within the canal. The distal fixation devices 330, 332 mayinclude a bone screw or anchor configured for distal locking of the nail309 and also reconstruction. The distal fixation device 330, 332 mayinclude traditional polyaxial or fixed angle locking bone screws andanchors known in the art.

In the illustrated embodiment, the distal openings include an AP lockingslot 312 and an AP locking opening 314. The openings also include a pairof ML locking openings 313, 315 and an ML locking slot 317. The AP andML locking slots 312, 317 facilitate relative movement between the nail309 and the locking screw 330 in the event compression or the like isapplied during installation. The distal openings also include a pair ofoblique openings 316, 318 configured to receive and guide reconstructionscrews 332. As illustrated in FIG. 9J, each of the oblique openings 316,318 is at an angle α₁, α₂ relative to the axis of the nail 309. Theangles α₁, α₂ are in the range of 45°-60°, and in the illustratedembodiment, are each 50°. It is preferred that the angles α₁, α₂ areequal to one another such that the oblique openings 316, 318 are mirrorimages of one another, thereby allowing the nail 309 to be utilized inboth right and left legs. The distal oblique openings 316, 318 allsurgeons to lock distal screws at an angle or approach a distal fragmentfrom a more proximal screw entry point. This configuration could beuseful for treatment of periarticular fractures and condylar splits.Additionally, the oblique distal openings 316, 318 allow surgeons toaccess condylar fractures without risking soft tissue damage near theknee or hip joint upon entry.

The proximal end 311 includes one or more proximal openings 123configured to receive one or more bone anchors or fasteners 330, 332that extend transversely through the proximal end 311 of theintramedullary nail 309, and are thereby configured to secure theproximal end 311 of the nail 309 within the canal and alsoreconstruction. The proximal fixation devices 330, 332 may include abone screw or anchor. The fixation device 330 may be a locking screw andthe fixation device 332 may be a calcar screw or anchor configured to beaimed at a calcar region of the proximal humerus, which may constitutethe best quality bone in the region.

The proximal openings may include a pair of ML openings 321, 323 and anML slot 325. The ML openings 321, 323 and the ML slot 325 are configuredto receive the locking screws 330. The ML locking slot 325 facilitatesrelative movement between the nail 309 and the locking screw 330 in theevent compression or the like is applied during installation. The distalopenings also include a plurality of oblique openings 322, 324, 326 and327, which preferably include mirrored pairs. More specifically, withreference to FIGS. 9K-9N, upper oblique openings 322 and 324 are mirrorimages, forming complementary angles β₁, β₂, i.e. β₁+β₂=180°. Forexample, the oblique angle β₁ may be about 100-150°, 110-140°, or about120-135° relative to the nail 309 while the angle β₂ is about 30-80°,40-70° or 45-60°. Similarly, the lower oblique openings 326, 327 aremirror images, forming complementary angles β₃, β₄, i.e. β₃+β₄=180°,which may extend over ranges similar to those given above for openings322, 324. With such a configuration, the proximal oblique openings 322,324, 326 and 327 are also aligned so that they will function the same ineither the right or left leg. In the illustrated embodiment, the anglesβ1 ₁, β₃ are equal and the angles β1 ₂, β₄ are equal, however, such isnot required.

Additionally, the openings whose axes are mirror images of one anotherare also offset in the AP plane from the sagittal plane, one by an θ₁ inthe anterior and the other by an angle θ₂ in the anterior. Asillustrated in FIGS. 9K and 9L, the opening 322 is offset by θ₁ whilethe opening 324 is offset θ₂. Similarly, as illustrated in FIGS. 9M and9N, the opening 326 is offset by θ₃ while the opening 327 is offset θ₄.In the illustrated embodiment, the larger offset θ₂, θ₄ is twice aslarge as the corresponding offset θ₂, θ₄. This creates room for thescrew 330 to pass posteriorly to these two reconstruction screws 332 tomake a fixed angle construct. In the illustrated embodiment, the offsetθ₁ of opening 322 is equal to the offset θ₄ of opening 327 while theoffset θ₂ of opening 324 is equal to the offset θ₃ of opening 326. Withthis configuration, the offsets of the similarly angled pair of openings322 and 326 will be offset with respect to one another and the offsetsof the similarly angled pair of openings 324 and 327 will be offset withrespect to one another.

The nail 309 provides a hybrid antegrade/retrograde and left/right nail.Such a nail 309 is advantageous to hospitals and surgeons because itreduces stock and simplifies surgical planning. The bi-directionalproximal oblique openings 322, 324, 326, 327 provide a variety ofoptions for proximal femur fracture fixation, as well as a more stableconstruct. Additionally, the arrangement of the proximal openings321-327 allows for a fixed-angle construct created by the screws 330,332. The design further provides for three screws to be secured into thefemoral neck. This fixed-angle construct provides more biomechanicalstability than the traditional two screw configurations.

Referring to FIGS. 91 and 11A-11E, a method of attaching theintramedullary nail 309 with an insertion tool 350 will be described.The nail 309 of the present embodiment has an opening 334 at theproximal end 311. A shoulder 335 within the opening 334 defines acircumferential slot 336 on the inside diameter of the proximal portion311 of the nail 309. This configuration takes up less space at theproximal end 311 of the nail 309 than a typical threaded connection,thereby freeing up space for more proximally located locking holes.

To connect the nail 309 to the insertion tool 350, the insertion tool350 includes an expanding collet 370 and connecting bolt 354. Analignment tip 360, which connects within a through passage 353 in theaiming arm 352 of the insertion tool 350, is configured to align thebolt 354 with the expanding collet 370. The alignment tip 360 includes ahollow body 362 with a through passage 364 extending from a proximal end361 to a distal end 363 of the body 362. The proximal end 361 of thebody 362 is configured to be received into the through passage 353 ofthe aiming arm 352 with a press fit, however, other connectingmechanisms may be utilized. A shoulder 368 extends radially from thebody 362 and engages the aiming arm 352 when fully inserted, asillustrated in FIGS. 11D and 11E. The distal end 363 of the body 362 hasa recessed portion 366 configured to be received into the opening 334 inthe proximal end of the nail 309.

The expanding collet 370 includes a hollow body 372 with a throughpassage 374 extending from a proximal end 371 to a distal end 373 of thebody 372. The distal end 373 has a radially outwardly extending collar376, tabs, projections or the like. The collar 376 is configured to bereceived within the circumferential slot 336 in the proximal end 311 ofthe nail 309. Axial slots 375 extend from the distal end 373 of the body372 and allow the distal end of the body 372 to compress radiallyinwardly, thereby allowing the collar 376 to pass through the alignmenttip through passage 364 and the shoulder 335 within the proximal end 311of the nail 309. An external shoulder 377 on the collet 370 contacts aninternal shoulder 367 on the alignment tip 360 to limit the range ofmotion of the collet 370 relative to the alignment tip 360. Once thecollar 376 is past the shoulder 335, the collar 376 is free to expandradially outwardly. The distal end 373 of the collet body 372 includesinternal threads 378 configured for engagement with the threads 355 ofthe connecting bolt 354.

The connecting bolt 354 then drives through the through passage 374 ofthe expandable collet 370 and engages the threads 378. As the connectingbolt 354 is threaded with the threads 378, it pushes the collar 376outwardly to its major diameter and further drives the collar 376 intothe circumferential slot 336 within the nail 309. In addition, when thebottom side of the head 356 of the bolt 354 makes contact with the topof the alignment tip 360, it allows for compression across the proximalnail 309, thus compressing any spacing in the connection. The assemblyallows for quick, easy, and rigid connection of the nail 309 to theaiming arm 352. It is noted that any of the intramedullary nailsdescribed herein may include an internal circumferential slot and beconnected to an insertion tool or the like utilizing an expanding colletas described.

Referring to FIGS. 12A-12K, a self-retaining screw 400 and driver 430assembly will be described. Screws are often affixed to drivers on theback table by a scrub tech or nurse and then they are handed to thesurgeon who places the screw where it is needed. Between the back table,and the final seating of the screw into the bone, many actions candislodge it from the driver, thus rendering it non-sterile, for example,when it hits the operating room floor. To minimize the likelihood ofdislodging, the self-retaining nail locking screw 400 has features whichachieve a more secure connection.

With reference to FIGS. 12A-12F, the screw 400 includes a shaft 402extending from a distal tip 404 to a proximal head 406. In theillustrated embodiment, the shaft 402 includes a two thread 403, 405start which provides for easier advancement. The head 406 defines aproximal torque bore 410 and a threaded bore 416 distally thereof. Thetorque bore 410 and the threaded bore 416 are in communication with oneanother and preferably coaxial. The torque bore 410 has a configurationwith engaging surfaces to engage a complimentary torque tool. In theillustrated embodiment, the torque bore 410 has a hexalobe configurationwith a plurality of lobal recesses 412 extending radially from thecentral opening. The lobal recesses 412 define a maximum diameter Dwhile the central opening defines a smaller diameter d. The lobalrecesses 412 are configured to receive complementary lobes 436 on adriving tool head 430, as will be described in more detail below. Thethreaded bore 416 defines a plurality of internal threads 417 which areconfigured to be engaged by a threaded rod (not shown) which tightensinto the threaded bore 416 at the bottom of the torque bore 410. Thecombination of a torque bore 410 and a threaded bore 416 allows forsecure delivery of the screw 400 utilizing the threaded rod andthereafter additional tightening of the screw 400, if needed, utilizinga torque driver engaged with the torque bore 410.

Referring to FIGS. 12G-12K, the torque driver head 430 illustratedtherein has a taper in order to give it a stab and grab retainingfeature on its own. The torque driver head 430 includes a proximal body432 and a distal shaft 434 extending therefrom. The proximal body 432and shaft 434 are preferably a unitary structure extending from aproximal end 431 to a distal end 433. A plurality of lobes 436 extendradially from the shaft 434 and have a complementary configuration tothe lobal recesses 412 in the torque bore 410 of the screw 400. Thelobes 436 taper, narrowing moving in the distal direction. The taper isgenerally constant over a first length Et and then more pronounced atthe distal end 433 over the length E₂. With the taper, the lobes 436define a larger maximum diameter Fi in the proximate portion of theshaft 434 (see FIG. 12J) and a smaller maximum diameter F₂ in the distalportion of the shaft 343 (see FIG. 12K). The larger diameter F₁ ispreferably larger than the maximum diameter D of the lobal recesses 412and the smaller diameter F₂ is preferably smaller than the maximumdiameter D of the lobal recesses 412, i.e. F₁>D>F₂. With thisconfiguration, the distal end 433 of the torque driver head 430 moveseasily into the torque bore 410, however, as the torque driver head 430is inserted further, the lobes 436 engage the lobe recesses 412 in afriction fit, providing the stab and grab retaining feature. In someinstances, this feature may provide sufficient secure connection withoutthe need to utilize the threaded rod and threaded bore 416.

Referring to FIGS. 13A-13F, a headless version of the screw 400′ will bedescribed. There are several scenarios in which a surgeon may desire tohave as low of a head profile on a screw as possible. For example, whena fracture occurs near the joint space, it is often necessary for asurgeon to place screws through the articular surface. In order topreserve function of the joint, and avoid joint pain, it is essentialthat the locking screw used does not impinge any motion of the bones orsoft tissues in that region. A headless screw may also be desired inareas where the soft tissue above the bone is very thin, so prominentscrew heads may be felt or even seen by the patient post-op (e.g., inthe proximal tibia).

The headless screw 400′ is similar to the screw of the previousembodiment and includes a shaft 402 extending from a distal tip 404 to aproximal head 406′. In the illustrated embodiment, the shaft 402includes a two thread 403, 405 start which provides for easieradvancement. Although it will be appreciated that the screw 400′ mayhave a single thread start or any other suitable configuration. Similarto the previous embodiment, the head 406′ defines a proximal torque bore410 and a threaded bore 416 distally thereof. The torque bore 410 has aconfiguration with engaging surfaces to engage a complimentary torquetool and the threaded bore 416 defines a plurality of internal threads417.

The head 406′ of the present embodiment, has a plurality of externalthreads 407. In the illustrated embodiment, the threads 407 may have afour start thread that is half the pitch of the shaft thread. Thethreads 407 allow the head 406′ to be sunk beneath the surface of thebone. When used in conjunction with the intramedullary nails describedherein or otherwise known, the headless screw 400′ provides a uniqueoffering of a headless option that still acts the same as a standardlocking screw.

According to an exemplary embodiment, an intramedullary nail systemincludes an intramedullary nail in combination with at least oneheadless screw or fastener. The intramedullary nail may includeintramedullary nails 109, 201, 309, 500 described herein or any otherintramedullary nails generally known or hereinafter developed. Theheadless screw or fastener is intended to encompass a screw or fastener,which is blind such that the screw is fully threaded and has no headprojecting past a major diameter of the screw thread and/or mayencompass a screw or fastener having a head portion where the threadextends all the way to the head (e.g., a threaded head). For example,the headless screw may include headless screw 400′ described herein orany other headless screw generally known or hereinafter developed.

According to one embodiment, the intramedullary nail 109, 201, 309, 500is used in combination with at least one headless screw 400′ or headlessfastener. The headless screw 400′ or other headless fastener may bepositioned through the body of the nail 109, 201, 309, 500 such that theshaft 402 resides within one or more openings in the nail 109, 201, 309,500. The shaft 402 of the headless screw 400′ may be configured to matewith the intramedullary nail 109, 201, 309, 500 in a locking (e.g.,threaded mating) or non-locking fashion. The threaded head 406′ of theheadless screw 400′ may be positioned such that the head 406′ ispositioned at or near the outer surface of the bone, for example, asbest seen in FIG. 9A. By positioning the head 406′ of the headless screw400′ against the bone (or slightly inset into the bone) in combinationwith the intramedullary nail 109, 201, 309, 500, the intramedullarysystem may be substantially unnoticeable to a patient. When traditionalheaded screws are used, sometimes patients complain that they are ableto feel the screw or the screw head protrudes from the surgical sitecausing irritation or pain to the patient. Accordingly, it may besuitable for one or more headless screws or fasteners to be used whensecuring the distal and/or proximal ends of the intramedullary nail,thereby resulting in superior patient outcomes.

Referring to FIGS. 14A-14C, a nail 450 with a threaded hole 454 will bedescribed. In unstable fractures or in patients with poor bone quality,it is imperative that the surgeon has an ability to stabilize thelateral translation of the nail relative to the screw. This is oftenreferred to as an interference fit. To achieve interference fit with thescrew 400 or a similar locking screw, the nail 450 is provided with oneor more threaded holes 454 along the elongate body 452 of the nail 450.The threaded hole 454 includes threads 453, 455 with a two start thread.In the illustrated embodiment, the threads 453, 455 provide a two start60-degree machine thread. The threads 453, 455 will have the same pitchas the threads 403, 405 of the screw 400. As previously described, thescrew shaft 402 also has a two start thread for easy advancement. Thethreaded two start hole 454 in the nail 450 itself is an advantage overcurrent interference holes because it is easy to manufacture, andrequires no additional steps or special techniques on the part of thesurgeon.

Referring to FIGS. 15A-15C, a washer 470 configured to provide greatercompression on the screw will be described. In some applications, thescrew and nail may not provide sufficient interference. For example,when poor bone quality or severely comminuted fractures interfere withscrew placement, surgeons often require a screw which interfaces withthe nail itself. When the near cortical wall is not stable, which is thecase in a number of complex femur fractures, even an interference fitscrew will not get any purchase in the near cortex, and therefore thefixation will be unstable. The washer 470 may be provided as an optionfor use with a screw and nail assembly if the conditions present theneed for such.

The washer 470 includes a hollow body 472 with a through passage 474extending from a proximal end 471 of the body 472 to a distal end 473 ofthe body 472. The distal end 473 of the body 472 includes a plurality ofcutouts 475 between distal tips 476. Each cutout 475 is approximately90° such that each pair of opposed cutouts 475 is coaxial therebyallowing an outer diameter of the nail. The washer 470 fits over themajor diameter of the screw and sits flush with the underside of thehead. It may be inserted through a tissue protection sleeve along withthe screw and driver. When the distal tips 476 of the washer 470 comeinto contact with the outer diameter of the nail and the nail isreceived into the opposed cutouts 475, the screw continues to spin whilethe washer 470 grips the side of the nail. This allows the screw to getcompression on the far side of the nail and hold the screw/washerconstruct firmly to the side of the nail. This provides a rigid fixationmethod when the cortical bone is not strong enough to do so. The washer470 thereby expands the indications for which the nail can be used.

Having described illustrative femoral nails, embodiments of tibial nailsand systems for implantation thereof will be described with reference toFIGS. 16A-17K. Referring to FIGS. 16A-16D, a first tibial intramedullarynail 500 will be described. It is recognized that the features of thenail 500 are not limited to use in a tibial nail and may be incorporatedinto other intramedullary nails. The intramedullary nail 500 generallycomprises an elongate body 502 extending from a first, distal portion orend 503 to a second, proximal portion or end 501. The elongate body 502may be in the form of an elongate tubular rod configured to extendlongitudinally within the intramedullary canal of a fractured bone. Theelongate rod may be hollow or may be solid along its length. Theelongate body may be substantially straight along a longitudinal axis ofthe nail 500 or may comprise one or more curves or bends to conform tothe anatomical shape of the intramedullary canal. In the embodiment ofthe nail 500 illustrated in FIGS. 16A-16D, the nail 500 is utilized in atibia and the proximal end has a bend λ relative to the shaft has a bendwhile the distal end has a bend χ relative to the shaft. In theillustrated embodiment, the bend λ is approximately 10° while the distalend bend χ is approximately 3°. The bends λ and χ are not limited to thedescribed angles and may have larger or smaller bends depending on theanatomy of the bone.

The distal end 503 of the tibial nail 500 contains four openings510-513. The openings 510, 512 are oriented in the ML direction and theopenings 511, 513 are oriented in the AP direction. In the illustratedembodiment, the ML opening 510 and the AP opening 511 each include a 2start thread 514 used to create a fixed angle construct with the lockingscrew, similar to that described above with respect to FIG. 14C. Fixedangle constructs are used to treat highly unstable fractures.

Referring to FIGS. 16E-16G, an alternative distal end 503′ of the nail500′ will be described. In this embodiment, the ML opening 510 isreplaced with a combined oblique locking opening 520, with first andsecond openings 521, 522 each at an oblique angle, for example, at 30°off the sagittal plane. The combined oblique locking opening 520 allowsthe surgeon to insert locking screws 530 in two different orientations,thereby creating an alternative fixed angle construct.

Referring to FIG. 16H, another alternative distal end 503″ of the nail500″ illustrates additional features which may be utilized to create afixed angle construct. In this embodiment, the AP opening 511′ isdefined as a broached hole while the AP opening 513′ is defined as athreaded hole. The fixed angle construct is created by inserting alocking screw through the threaded or broached hole. The locking screwthread engages with the threads or broached features to stabilize thefracture by limiting the movement of the screw 530 relative to the nail500″.

Returning to FIGS. 16A and 16C, the proximal end 501 of the tibial nail500 contains openings 515-518, including a pair of proximal obliqueopenings 515, an AP oblique opening 516, a proximal ML slot 517 and aproximal ML opening 517. The proximal oblique openings 515 are similarto those describe above with respect to the embodiment illustrated inFIG. 9A. The AP oblique opening 516 contains a 2 start thread 519 usedto create a fixed angle construct with a locking screw. The proximal MLslot 517 is used for compression of fractures and static/dynamic lockingmodes.

Having described various features of illustrative tibia nails 500,tools, systems and methods of inserting the tibia nails 500 will bedescribed with reference to FIGS. 17A-17K. The tibial nail 500 isinserted into the medullary canal through an incision at the entry site.FIG. 17A illustrates an illustrative embodiment of a system 535 forimplanting an intramedullary nail 500 utilizing the infra-patellarapproach. The infra-patellar approach is the industry standard approachfor insertion of the tibial nail 500. This approach is typicallyperformed with the leg in the hyper-flexed (HF) position. The tibialnail 500 is inserted directly through the incision into the tibialcanal.

The system 535 includes an insertion tool 540 and an aiming guide 560.The insertion tool 540 includes a coupling portion 545 and a handleportion 547. In some embodiments, the coupling portion 545 and thehandle portion 547 can be separate parts that are removably joinedtogether, while in other embodiments the coupling portion 545 and thehandle portion 547 can be different regions of a single, integrallyformed component. The handle portion 547 is preferably rigid, forexample, made from stainless steel and also has provisions to attach animpaction shaft 546 and compression bolt 544. The coupling portion 545has a connection portion 548 configured to releasably engage or coupleto the proximal portion 501 of the nail 500. In the illustratedembodiment, the connection portion 548 includes a threaded connector.However, those skilled in the art will understand that other couplingmechanisms may be employed.

The handle portion 547 includes a connection assembly 550 for releasablyattaching the handle portion 547 to the aiming guide 560. The connectionassembly 550 includes a body 551 with two bores 552, 554 definedtherein. A connection button 553 extends into one of the bores 552. Theconnection button 553 is biased to a connected position as illustratedin FIG. 17B. The connection button 553 has an engagement portion 556within the bore 552 configured to engage a slot 573 on a connection post572 of the aiming guide, as will be described in more detailhereinafter. In the illustrated embodiment, the engagement portion 556includes a plate with a smaller diameter opening 557. To disengage theengagement portion 556, the button 553 is depressed such that the largerdiameter opening 558 aligns with the connection post 572. However, thoseskilled in the art will understand that other connection mechanisms maybe employed.

The tibial nail aiming guide 560 is used to install locking screws intothe tibial nail 500. The aiming guide 560 sets the trajectory of thelocking screws to interface with the proximal openings 515-518 of thenail 500. In at least one embodiment, the aiming guide 560 is made froma radiolucent material. The aiming guide 560 includes an arcuate body562 which extends between opposed end support blocks 564. Each endsupport block 564 defines a hole opening 563, which aligns with the MLopening 518, and a slot opening 565, which aligns with the ML slot 517.A plurality of intermediate support blocks 568A-C extending from thebody 562. The support block 568A includes a hole opening 569 which isaligned with the AP oblique opening 516. The support blocks 568B and568C each include a hole opening 569 which is aligned with a respectiveoblique opening 515. The openings 563, 565, and 569 are configured tosupport respective guide sheaths 580 similar to the guide sheaths 117described above. The sheaths 580are used to protect the soft tissueduring the drilling process. The sheaths 580 accept drill sleeves andtrocars of various sizes. The guide sheaths 580 and blocks 564, 568A-Cmay have retention members similar to those described above, with eachblock 564, 568A-C having a respective release mechanism 567.

The aiming guide 560 also includes a connection assembly 570 configuredto mate with the connection assembly 570 on the insertion handle 540.The connection assembly 570 includes a body 571 with a pair ofconnection posts 572, 574 extending therefrom which are configured to bereceived in the bores 552, 554 of the connection assembly 550. Theconnection post 572 includes a slot 573 configured to be selectivelyengaged by the engagement portion 556 of the connection button 553. Theconnector assembly 570 is a rigid structure and may be made from, forexample, metal.

Accordingly, the system 535 provides an insertion handle 547 withreliable and convenient connection assembly for attaching the aimingguide 560. A push button connection and release system allows tool freeconnection and disconnection of the aiming guide 560. The insertionhandle 547 also contain an external compression bolt 544 used to applypressure the locking screw in the dynamic position to compress afracture gap. The aiming guide 560 utilizes a push button releasemechanism 567 that locks the soft tissue sheaths 580 in place. Therelease mechanism 567 allows insertion of the soft tissue sheath 580 butprevents it from backing out. This feature helps to maintain theposition of the soft tissue sheaths 580 for accurate screw lengthmeasurements and facilitates drilling and screw insertion. The aimingguide 560 is designed with extended sheath guides 580 for improvedaiming accuracy.

The supra-patellar approach uses a tibia entry point above the knee. Asystem 530′ for use with the supra-patellar approach will be describedwith reference to FIGS. 17F-17L. The system 530′ is substantially as inthe previous embodiment but further includes a cannula assembly 590. Asillustrated in FIG. 17F, at the time of insertion of the nail 500, thenail 500 and the connection portion 545 of the insertion tool 540 areinserted through the cannula assembly 590. The cannula assembly 590protects the articular surface of the knee during the nail insertionprocess. As will be described below, the cannula assembly 590 alsoprotects the articular surface of the knee during reaming. The reamingis performed through a drill guide 610 in the cannula 592 of the cannulaassembly 590. Thereafter, the drill guide 610 is removed and nail 500insertion is performed through the cannula 592 into the entry incision.

Referring to FIG. 17G, an illustrative cannula assembly 590 will bedescribed. The cannula assembly 590 includes a flexible cannula 592 anda rigid handle 596. The cannula 592 has a through passage 594 which isaligned with an opening 599 in the handle 596 to define a continuouspassage. In one embodiment, the flexible cannula 592 material isover-molded onto the rigid plastic handle 596. A pair of tibia guideslots 595 extend through the handle 596 and along the sides of thecannula 592. Transverse femur guide holes 597 extend through the handle596. As shown in FIG. 17H, the guide slots 595 and guide holes 597 guidefixation pins 602 into the tibia 144 or femur 143.

The cannula assembly 590 is inserted through an incision in the skin andis the working portal through which the surgeon can perform reaming,drilling, and nail insertion. The guide slots 595 and holes 597 allowthe surgeon to fix the cannula 592 in place during the procedure. Theguide slots 595 and holes 597 allow the cannula to be fixed to the femur143 or tibia 144 with converging pins 602 depending on surgeonpreference. The cannula 592 is reversible and can be used on either sideof the patient. Referring to FIG. 171, the cannula assembly 590 isdesigned to accept a metal drill sleeve 610 and round trocar 612. Thereis a connection point 603 on the cannula handle 596 that accepts theconnector 611 on the metal drill sleeve 610. In the illustratedembodiment, the cannula 592 is tapered for easy removal of the drillsleeve 610. The soft, flexible cannula 592 is anatomically shaped to fitbetween the femoral condyles and minimize damage to the articularsurface.

Referring to FIGS. 17J-L, a cannula assembly 590′ in accordance withanother illustrative embodiment will be described. The cannula assembly590′ is similar to the previous embodiment and includes a flexiblecannula 592′ extending from a rigid hub 596′. The rigid hub 596′includes legs 593 extending from each side of the cannula 592′. Each leg593 of the hub 596′ defines a respective tibia fixation hole 595′ and aseries of femur pin holes 597. The two tibia fixation holes 595′ aredesigned to accept k wire or pin 602 for fixation to the tibia. Thewires or pin 602 can be convergent or parallel. The femur pin holes 597are for femur fixation using half pins 598. The cannula assembly 590′ isdesigned to accept a metal drill sleeve 610 and round trocar 612.

Referring to FIG. 18, an aiming guide 601 is provided for inserting anintramedullary nail into a bone, such as a femur 143 (shown in FIGS.3A-3F). The aiming guide 601 provides the ability to insert femoralnails through both a piriformis and a greater trochanter entry point,allowing for antegrade and retrograde nail implementation. Additionally,the aiming guide 601 allows for the attachment of an impactor andmultiple modules, which allows for simple operation of the aiming guide601 while still allowing for a variety of engagement options for theclinician. Also, the aiming guide 601 provides a rigid connection to thenail to assist with insertion into the femur, and the base for anassembly that provides for a method to insert both recon fasteners orscrews and oblique fasteners or screws to secure the femoral nail intothe femur. Although described with reference to an antegrade/retrogradefemoral nail, it will be appreciated that a similar aiming guide may beprovided with other intramedullary systems.

The nail can be nail 309, shown in FIG. 9A, nail 500, shown in FIG. 17F,nail 699, shown in FIGS. 23-26, or other suitable intramedullary nailsystems. The aiming guide 601 may be used to install recon fasteners orscrews, oblique fasteners or screws and/or lateral/medial lockingfasteners or screws into the intramedullary nail. The aiming guide 601is configured to set the trajectory of the fasteners or screws tointerface with corresponding through holes in either or both theproximal end and the distal end of the nail. A tissue sleeve may be usedto protect soft tissue during the drilling process and to help set thedrill trajectory.

The aiming guide 601 may include a generally arcuate or “J-shaped” body605 having an elongate proximal handle portion 604 and a generallyarcuate distal implant alignment tip connector portion 606. The distalimplant tip connector portion 606 has a distal implant alignment tip 608that may be configured to extend along a tip axis 613 substantiallyparallel to a longitudinal axis 615 of the proximal handle portion 604.The distal implant alignment tip 608 may be secured to the distalimplant tip connector portion 606, for example, via spring loadedfriction pads (not shown) located on the distal implant tip connectorportion 606 that help keep the distal implant alignment tip 608 inplace. The distal implant alignment tip 608 may also be secured, forexample, in the manner provided in FIG. 11A.

According to one embodiment, the aiming guide 601 including the body 605and implant alignment tip connector portion 606 may be a unitaryconstruction that is constructed from a single material, such as, forexample carbon fiber. The distal implant alignment tip 608 mayoptionally be constructed from a different material, such as, forexample, a metal such as steel. The metal allows for an impactor (notshown) to be directly threaded into the distal implant alignment tipconnector portion 606.

Further, the distal implant alignment tip 608 may be inserted into areceiver 614 at the distal end 617 of the distal implant alignment tipconnector portion 606 for a releasable connection with the distalimplant alignment tip connector portion 606. The distal implantalignment tip 608 is configured to releasably retain a femoral nail,such as nail 309, a nail 500, or a nail 699, as discussed above.

A proximal end 616 of the handle portion 604 may have a first attachmentlocation 618 for releasably attaching a first module, such as, forexample, a recon module 700, shown in FIG. 19. The first attachmentlocation 618 includes a recessed portion 620 on an exterior side 622 ofthe handle portion 604. A threaded receiver 624 extends into the handleportion 604 from the recessed portion 620 and is sized to threadinglyengage a thumb screw 702 on the recon module 700. A generally oblongalignment bushing 625 may surround the receiver 624.

The proximal handle portion 604 may include a hand grip 630 on aninterior side 632 of the handle portion 604. The hand grip 630 includesa plurality of finger indents 634 to allow a clinician to grip thehandle portion 604 and reduce the likelihood of the handle portion 604rotating in the clinician's handle while using the aiming guide 601. Thehand grip 630 has a plurality of through holes 636 extendingtherethrough from the exterior side 622 to the interior side 632. Atleast one of the through holes 636 extends along a hole axis thatextends substantially perpendicular to the longitudinal axis 615 of thehandle portion 604. In an exemplary embodiment, each of the throughholes 636 extends along a hole axis that extends substantiallyperpendicular to the longitudinal axis 615 of the handle portion 604.

Through holes in the aiming guide and/or modules can be used to alignsleeve 340, 342, 344 and screw 330, 332 with the femoral nail 699. Asshown in FIG. 26, through hole 636 can align sleeve 344 and screw 330with an opening in the femoral nail 699. The sleeve 344 can be similarto the sleeves or sheaths described herein (e.g., sheath 117) configuredto protect soft tissue and allow for insertion of a drill, driver,fasteners or screws (e.g., fastener 119, fixation devices 330, 332), andthe like configured to be aligned with and inserted through the openingsin the intramedullary nail and into the bone.

Distal from the handle portion 604, the distal implant alignment tipportion 606 further includes a second attachment location 640 forreleasably attaching a second module, such as, for example, an obliquemodule 800, shown in FIG. 20. The second attachment location 640 mayinclude a metal alignment block 642 on each side wall 644, 645 (sidewall 645 is shown in FIG. 21) of the distal implant alignment tipportion 606. The alignment blocks 642 may be used to align the obliquemodule 800 on the body 605. Pins 648 fit into holes 647 in the alignmentblocks 642 (only one alignment block 642 is shown) to retain thealignment blocks to the body 605. A threaded receiver 646 extendsthrough the distal implant alignment tip portion 606 between thealignment blocks 642 and is sized to threadingly engage a thumb screw802 on the oblique module 800 (shown in FIG. 20). The distal implantalignment tip portion 606 further comprises a third attachment location650 for releasably attaching an impactor attachment (not shown) tosupport the impactor discussed above. The third attachment location 650can be a threaded opening to receive a threaded insert on the impactorattachment.

Referring to FIGS, 19 and 21, the recon module 700 may be releasablyattached to the proximal end 616 of the proximal handle portion 604. Therecon module 700 includes a connection piece 704 that engages theproximal end 616 of the proximal handle portion 604. The connectionpiece 704 includes a recessed portion 706 that mirrors the recessedportion 620 in the proximal end 616 for a secure engagement. Recessedportion 706 includes a generally oblong receiver 708 that is sized toaccept the generally oblong alignment bushing 625 to prevent translationor rotation of the recon module 700 with respect to the aiming guide601. With the generally oblong alignment bushing 625 inserted into thereceiver 708, the thumb screw 702 is aligned with the threaded receiver624 so that the recon module 700 can be releasably secured to the aimingguide 601 by threading the thumb screw 702 into the threaded receiver624.

The recon module 700 may have an arcuate body 710 having a first reconportion 712 extending from the first side wall 644 of the proximalhandle portion 604 and a second recon portion 714 extending from thesecond side wall 645 of the proximal handle portion 604, distal from thefirst side, when the recon module 700 is attached to the aiming guide601, as shown in FIG. 21. The arcuate body 710 has a plurality of reconthrough holes 720, 722, 724, 726 extending therethrough, such that eachof the plurality of recon through holes extends along an axisintersecting the tip axis 613.

Referring to FIGS. 20 and 21, the oblique module 800 may be releasablyattached to the distal implant alignment tip portion 606. The obliquemodule 800 includes a generally U-shaped attachment site 803 thatengages the alignment blocks 642 when the oblique module 800 is insertedonto the aiming guide 601 so that the thumb screw 802 is aligned withthe threaded receiver 646. The oblique module 800 can be releasablysecured to the aiming guide 601 by threading the thumb screw 802 intothe threaded receiver 646.

The oblique module 800 may have an elongate body 804 having a firstoblique portion 806 extending from a first side of the attachment site803 and a second oblique portion 808 extending from a second side of theattachment site 803, distal from the first side., when the obliquemodule 800 is attached to the aiming guide 601, as shown in FIG. 21. Theelongate body 804 has a plurality of oblique through holes 810, 812,814, 816 extending therethrough, such that each of the plurality ofoblique through holes 810, 812, 814, 816 extends along an axisintersecting the tip axis 613.

Aiming guide 601, recon module 700, and/or oblique module 800 may forman aiming guide assembly that supports a plurality of screws 330, 332inserted therethrough and into femoral nail 699, as shown in FIGS.23-26. In FIGS. 23 and 24, two recon screw sleeves 340 are shownextending through recon module 700 to align recon fasteners 332 with theintramedullary nail 699 for placement of the recon fasteners 332; inFIG. 25, a single recon screw sleeve 340 extends through recon module700 for placement of the recon fastener or screw 332 in the femoralhead, while a single oblique screw sleeve 342 extends through theoblique module 800 for placement of the oblique screw 332 through thenail 699 into the greater trochanter of the femur and preferably not thelesser trochanter of the femur; and in FIG. 26, a single oblique screwsleeve 342 extends through the oblique module 800, while a single driverscrew sleeve 344 extends from the handle portion 604 of the aiming guide601 for placement of screw 330 into the femoral nail 699. While theseexemplary embodiments of screw sleeves 340, 342, 344 and screwconfigurations are shown, those skilled in the art will recognize thatother sleeve and screw configurations can be provided with the aimingguide assembly.

While the recon module 700 and the oblique module 800 are shown with theaiming guide 601, those skilled in the art will recognize that the reconmodule 700 and the oblique module 800 can be used independently oromitted and just the aiming guide 601 alone can be used with the femoralnail 699 and one or more sleeves 340, 342, 344 through the aiming guide601 for placing fasteners or screws 330, 332 into the femoral nail 699.

Referring now to FIG. 27, an alternative embodiment of an aiming guide900 is similar to the aiming guide 601, but instead of being of unitaryconstruction from a single material, the aiming guide 900 can be amulti-part construction body 902 with a handle portion 904 constructedfrom a first material, such as, for example carbon fiber, and an aimingarm portion 906 constructed from a second material, such as, for examplea metal or plastic.

As shown in FIG. 27, the handle portion 904 has a generally rectangularmale insert 910 that is sized and shaped to fit into a generallyrectangular female receiver 912 in the aiming arm portion 906. Theinsert 910 has a plurality of locking holes 914 that align with a likeplurality of locking holes 916 in the aiming arm portion 906 such that,when the insert 910 is inserted into the receiver 912, the locking holes914, 916 align with each other to allow pins (not shown) to be insertedtherein to secure the aiming arm portion 906 to the handle portion 904.

The aiming arm portion 906 also includes an attachment location in theform of a threaded opening 950 for directly connecting the impactordiscussed above to the aiming arm portion 906.

Operation of the aiming guide 900 is similar to the operation of theaiming guide 601 as discussed above. The recon module 700 and theoblique module 800 can each be releasably secured to the aiming guide900 to assist in aiming screw sleeves 330, 331, and 340, andcorresponding screws, for example, into the nail 699.

Referring now to FIG. 28, an exemplary aiming guide 1000 consistent withthe principles of this disclosure is illustrated. Aiming guide 1000 maybe similar to the aiming guides previously described. Also illustratedare collet 1002 and connection bolt 1004, which may also be similar tocomponents previously described. In order to connect connection bolt1004 to collet 1002 (and nail 1018 as previously described), aconnection bolt driver 1006 may be used. Connection bolt 1004 may beinserted or removed from aiming guide 1000 through the use of connectionbolt driver 1006. Connection bolt 1004 may be configured to beself-retaining. For example, according to an exemplary embodiment,connection bolt 1004 may be retained by bolt driver 1006 through aninterference fit that allows bolt driver 1006 to be retained inside ahead 1008 of connection bolt 1004.

FIGS. 29A-29B illustrate an example of connection bolt 1004 thatprovides a self-retaining connection to bolt driver 1006. Connectionbolt 1004 may include a circlip 1010 disposed inside of head 1008, whichmay include a hex recess 1012 configured to receive a portion of driver1006. Connection bolt 1004 may be configured to include a radial groove1014 into which circlip 1010 may be loaded. Circlip 1010 may then act asa spring to provide interference which retains bolt driver 1006 insidehead 1008 of connection bolt 1004. Bolt driver 1006 may include a hexshaped end 1016 that inserts into hex shaped recess 1012. As bolt driver1006 is inserted into head 1008, end 1016 may splay open circlip 1010 toseat it in groove 1014. Circlip 1010 may have a spring tension thatholds bolt driver 1006 inside of head 1008 which is illustrated in FIG.30.

As described above, the circlip feature allows for self-retention of theconnecting bolt to the bolt driver. This provides easy insertion andremoval of the bolt and minimizes risks of the connection boltunintentionally falling to the ground or into soft tissue of a patient.This may also provide a user with options for an angled approach to thehead of the connection bolt, which may allow easier passage aroundcertain soft tissue structures.

The above detailed descriptions of embodiments of the technology are notintended to be exhaustive or to limit the technology to the precise formdisclosed above. Although specific embodiments of, and examples for, thetechnology are described above for illustrative purposes, variousequivalent modifications are possible within the scope of thetechnology, as those skilled in the relevant art will recognize. Forexample, while steps are presented in a given order, alternativeembodiments may perform steps in a different order. The variousembodiments described herein may also be combined to provide furtherembodiments.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but well-known structures and functions have not been shown or describedin detail to avoid unnecessarily obscuring the description of theembodiments of the technology. Where the context permits, singular orplural terms may also include the plural or singular term, respectively.

It will also be appreciated that specific embodiments have beendescribed herein for purposes of illustration, but that variousmodifications may be made without deviating from the technology.Further, while advantages associated with certain embodiments of thetechnology have been described in the context of those embodiments,other embodiments may also exhibit such advantages, and not allembodiments need necessarily exhibit such advantages to fall within thescope of the technology. Accordingly, the disclosure and associatedtechnology can encompass other embodiments not expressly shown ordescribed herein.

What is claimed is:
 1. An aiming guide for inserting an intramedullarynail into a bone, the aiming guide comprising: a collet configured toengage the intramedullary nail; a connection bolt configured to engagethe collet to connect the collet with the intramedullary nail; and aconnection bolt driver configured to engage the connection bolt, whereinthe connection bolt comprises a head containing a circlip, the circlipconfigured to splay open upon insertion of the connection bolt driverinto the head and provide tension around the connection bolt driver toretain the connection bolt driver in the head of the connection bolt. 2.The aiming guide according to claim 1, wherein the collet is configuredto expand to engage an opening of the intramedullary nail.
 3. The aimingguide according to claim 2, wherein the collet includes a hollow bodywith a through passage from a proximal end to a distal end of thecollet.
 4. The aiming guide according to claim 3, wherein the distal endof the collet has a radially outwardly extending collar.
 5. The aimingguide accordingly to claim 4, wherein the collar is configured to bereceived in the opening of the intramedullary nail.
 6. The aiming guideaccordingly to claim 5, wherein the distal end of the body containsaxial slots.
 7. The aiming guide accordingly to claim 6, wherein thedistal end of the collet contains internal threads.
 8. The aiming guideof claim 7, wherein the connection bolt engages the internal threads toexpand the collet within the opening of the intramedullary nail.
 9. Theaiming guide of claim 1, wherein the circlip is disposed in a radialgroove of the head of the connection bolt.
 10. The aiming guide of claim1, wherein the head contains a hex-shaped recess that engages theconnection bolt driver.
 11. An aiming guide for inserting an implantinto a bone, the aiming guide comprising: a collet configured to engagethe implant; a connection bolt configured to engage the collet toconnect the collet with the implant; and a connection bolt driverconfigured to engage the connection bolt, wherein the connection boltcomprises a head containing a circlip, the circlip configured to splayopen upon insertion of the connection bolt driver into the head andprovide tension around the connection bolt driver to retain theconnection bolt driver in the head of the connection bolt.
 12. Theaiming guide according to claim 11, wherein the collet is configured toexpand to engage an opening of the implant.
 13. The aiming guideaccording to claim 12, wherein the collet includes a hollow body with athrough passage from a proximal end to a distal end of the collet. 14.The aiming guide according to claim 13, wherein the distal end of thecollet has a radially outwardly extending collar.
 15. The aiming guideaccordingly to claim 14, wherein the collar is configured to be receivedin the opening of the implant.
 16. The aiming guide accordingly to claim15, wherein the distal end of the body contains axial slots.
 17. Theaiming guide accordingly to claim 16, wherein the distal end of thecollet contains internal threads.
 18. The aiming guide of claim 17,wherein the connection bolt engages the internal threads to expand thecollet within the opening of the implant.
 19. The aiming guide of claim11, wherein the circlip is disposed in a radial groove of the head ofthe connection bolt.
 20. The aiming guide of claim 11, wherein the headcontains a hex-shaped recess that engages the connection bolt driver.